Displaying 20 results from an estimated 500 matches similar to: "Order of terms in formula changes aov() results"
2010 Feb 19
3
Omitting members of a sequence
Hello, this is just a point of curiosity with me. I want a sequence of
numbers from 64 to 70, omitting the 2nd and 4th numbers. I can do it
these ways:
> seq(64, 70)[-c(2, 4)]
[1] 64 66 68 69 70
> foo <- 64:70
> foo[-c(2, 4)]
[1] 64 66 68 69 70
But how come this doesn't work?
> 64:70[-c(2, 4)]
[1] 64 65 66 67 68 69 70
Just wondering.
--
Stuart Luppescu -=- slu .at.
2011 Aug 16
2
Assignment working differently inside ifelse()
Hello all, I need to extract rows and columns from a data frame and put
them in a matrix. In some cases, there are no rows in the data frame
meeting the selection criteria. For those rows I want to put a row of
0's in the matrix. Here's my clumsy code:
tab1.m1 <- matrix(0, nrow=2, ncol=4)
tab1.m1[1,] <- ifelse(length(as.matrix(tab1[tab1$comp==the.comp & tab1$schlid==the.schl
2011 Jan 23
2
Ordering box plots
Hello all, I want box plots by group to display in order of increasing
mean (or median) of each group but can't seem to figure it out and
couldn't find anything on R-seek, either.
My data looks like this:
meas unit sid grade rsprti
1 2.24 1002 99999902 NA 0.8600000
2 3.04 1007 43589520 3 0.9400000
3 4.95 2002 39910470 5 1.5300000
4 2.24 2002 39986280 5
2010 Apr 06
2
help in function in R akin to macro in SAS
Dear Whom it may concern,
I need help to figure the "macro" function in R: I need to plot the
different data sets by a plotxyf function, I want the title to be different
for different data set.
# get the data set
final.xyf<- xyf(data=as.matrix(my.final),
Y=classvec2classmat(final$outcome), xweight = 0.5, grid=somgrid(5, 4,
"hexagonal"))
#plot function
2011 Apr 21
1
Stymied by plyr
Hello, This is my first time trying to use plyr, and I'm getting
nowhere. I have teacher ratings data (1:4), on 10 components, by
external observers and internal observers, in schools in areas. I want
to calculate the percentage of each rating given on each component, by
each type of observer, within each school, within each area. The data
look like this:
unit area ext.obs rating comp
11
2012 Apr 16
3
Select rows based on condition
Hi,
I am relatively new to R and I am trying to figure out how to select rows of
my data based on a condition.
For example in the dataset below multiple observers recorded data at the
same point on the same date and the data was recorded on separate rows, but
I only need one of the rows of data. Is it possible to use grep to search
for rows that have matching PtName and Date and then select the
2011 Nov 20
1
Need help with table() and apply()
Hello, I am having trouble getting counts of values in rows of a data
frame. I'm trying to use apply, but it's not working.
This gives a sample of the kind of data I'm working with:
rating.1 <- factor(sample(1:4, size=10, replace=T), levels=1:4)
rating.2 <- factor(sample(1:4, size=10, replace=T), levels=1:4)
rating.3 <- factor(sample(1:3, size=10, replace=T), levels=1:4)
2002 Aug 02
3
I know this is wrong, but why?
My mind has become corrupted by having to use SAS too much. I wanted to
calculate the difference of elements of two vectors if the signs are the
same. I tried it the corrupted way first:
if (effects1[,3] < 0 & effects0[,3] < 0) {
imprv1 <- effects0[,3] - effects1[,3]
} else if (effects1[,3] > 0 & effects0[,3] > 0) {
imprv1 <- effects1[,3] - effects0[,3]
} else {
2010 Jun 29
2
Conditionally constructing columns in a data frame
Hello, I have to construct 5 new columns in a data frame depending on
the value of another of the columns in the data frame. The only way I
could figure out to do this was to subset the data frame five times, do
the variable construction, and then rbind the subsets back together.
Here's part of the code I used:
read001 <- read[read$existstr=="001",]
read001$era1end <- NA
2007 Apr 18
1
[Bridge] Problem loading bridge.o
Hello, I want to add wireless capability to my Gentoo-linux based
firewall/router at home, so I bought a Netgear MA311 PCI and installed
the hostap package. I load the hostap_pci module and the wlan0 interface
comes up fine. I can detect the signal from a wireless enabled laptop.
Now I'm thinking I'm going to bridge the wlan0 interface and the eth1
interface, and run the firewall with br0
2008 Jul 12
1
a warning message from lmer
Hi all,
I have a problem when running lmer.
In my data set, Agree is a binary(0/1) response. WalkerID and ObsID is
the identification number of the subjects. the description of the
other variables are as follows:
> levels(regdat$Display)
[1] "Dynamic" "Static"
> levels(regdat$Survey)
[1] "HM1_A" "HM1_B" "HM1_C" "HM2_A"
2010 Sep 01
5
[semi-OT] Using fortune() in an email signature
Hello, As you can see from my signature in this message, I use the R
fortune function to generate a fortune, which is then fed to the
signature program, which constructs a named pipe containing the
fortune-bearing sig, which is then included in mail messages. The
problem is that it's got extraneous junk in it and I can't figure out
how to get rid of it. This is the command that generates
2002 May 19
3
How to shade part of a density plot
I'm trying to shade part of a density plot. The code I'm trying (using
the Old Faithful data as an example) is something like this:
# The Old Faithful geyser data
data(faithful)
d <- density(faithful$eruptions, bw = "sj")
plot(d)
polygon(d[d$x>4], col = "wheat")
I expected that the part of the curve to the right of 4 on the x axis
should be shaded, but nothing
2004 Oct 11
3
split and rlm
Hello, I'm trying to do a little rlm of some data that looks like this:
UNIT COHORT perdo adjodds
1010 96 0.39890 1.06894
1010 97 0.48113 1.57500
1010 98 0.36328 1.21498
1010 99 0.44391 1.38608
It works fine like this: rlm(perdo ~ COHORT, psi=psisquare)
But the problem is that I have about 100 UNITs, and I want to do a
2011 May 09
2
Creating Observation ID
If I have a data frame something like:
Value=rnorm(30)
Group = sample(c('A','B','C'), 30, replace=TRUE)
df = data.frame(Value, Group)
It seems like it should be simple to create an 'ObsID' column which indicates the observation order of each Value within each of the 3 groups. Somehow, I can't quite see how to do it without manually sub-setting the parent data
2010 Jul 05
3
How to determine if R is 64 bit compiled under Unix-alike?
Under MacOS I had R64 executive and it was clear. Under Ubuntu, which I
do not have administrative rights to, there is only R executive. It
seems that I can allocate more than 3GB of memory, however not
everything seems to work the same/right as with R64 under MacOS.
Pms.
2010 Jul 14
1
Multilevel IRT Modelling
Dear All,
does anybody know of a package (working under Linux) for multilevel IRT
modelling?
I'd love to do this without having to go on WINSTEPS or the like..
thanks for the attention!
Federico Andreis
-----
Dr. Federico Andreis
Universit? degli Studi di Milano-Bicocca, PhD Student
MEB Department, Karolinska Institutet, Stockholm, Visiting PhD Student
--
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2001 Dec 13
3
emacs 21.1, R-1.3.1, and ESS
On RedHat linux 7.2, I upgraded (?) Emacs and R at the same time and now
I'm getting some funny business with R and ESS. I reinstalled ESS from
the tarball and re-byte-compiled. In particular, help.start() does
work, and ESS works to send text regions to the R process, but ?function
does not return anything, and the status line says
"ESS process not ready. Finish your command
2010 Mar 03
1
help R IRT simulation
hello R,
This is about simulation in psychomtrics in IRT in R. I want to simulate b
parameters(item difficulty) with moments of fixed values of mean, st.d,
skewness and kurtosis. Is there any specific IRT package in R with those
functions to control those moments? I have seen other programs that can
control mean and st.d but not skewness and kurtosis.
Thank you,
helen L
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2010 Aug 23
5
trajectory plot (growth curve)
Hi there,
I want to make trajectory plots for data as follows:
ID time y
1 1 1.4
1 2 2.0
1 3 2.5
2 1.5 2.3
2 4 4.5
2 5.5 1.6
2 6 2.0
...
That is, I will plot a growth curve for each subject ID, with y in
the y axis, and time in the x axis. I would like to have all growth
curves in the same plot. Is there